Hi,
is there by chance another SERVICE GUIDE ANALYSIS FOR YAMAHA ELECTONE PAS for sale?
Or can you give me a copy of it? I have an e70 with serious problems and want to solve the but technicians haven´t been able to. Anyone that can help me with an e70 problem? sound in flutes are failing. Lower notes have no volume but it increases with higher notes. My guess is that notes are contructed with armonics sounds but some are missing, the lower ones. Is this crazy? Some idea where should we check? The yamaha technician hasn´t been able to solve it.
Thanks
Michael
mleydar@cantv.net

Hmm, I suppose your tech should really be looking at materials on the CS-80 since this synth is derived from that one. They use the same circuits (almost).

Quote:

My guess is that notes are contructed with armonics sounds but some are missing, the lower ones.

Well, close! You start with a harmonic-rich signal and take out the ones you don't want, generally. So perhaps your problem has to do with a stuck high-pass filter. If it happens for all voices than I would suspect the filter key tracking circuit. But really, you'd need to describe the problem in a lot more detail for one to even guess.

When you use the 1, 2 and 3 pistons, the organ seems to work fine, but as soon as you cancel and tried to use the 16th flute, the volume is very poor in two keyboard and the pedal. It increases with the higher notes. That is my guess that lower notes has lost some of the harmonics, i don´t know if this is the right name.

So it sounds not only too quiet but also thin (meaning bass light or, if you like, "tinny")?

If you hold down a higher note and then play a low one, does it still happen? What if you hold 3 or 4 or 5 and then press a low note? The result for what the low note sounds like is the same?

Hi,
The second question:
I tried that and the volume is the same in the lower and upper notes, same in the upper and lower keyboard. I was playing chord on the higher notes and playing a melody on the lower notes. No difference in the volume.

Okay, I think I was probably on the wrong track. It's weird that the preset pistons work normally.

I wish I knew more about how organ consoles map to synthesizer controls!

These things have a control voltage mixer for the filter cutoff frequency - the problem could be in there. But I think you should try to listen to the output of the voice board mix before it goes into the ring modulator. This might be labeled "O1" on the "PRA" board, according to the CS-80 block diagram I'm looking at. If it sounds normal there than there's some failure in the final stages.

Hi,
I uploaded almost all of the videos. I`m including also some with voltage checking, etc. If you don´t have a e70 service manual, it can be downloaded from the net. Let me know and i`ll give you the link.
Bye
Mike

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